[zeromq-dev] Remote client does not receive any messages
Trevor Bernard
trevor.bernard at gmail.com
Mon Dec 1 23:53:49 CET 2014
s/ncat/netcat/
On Mon, Dec 1, 2014 at 6:52 PM, Trevor Bernard <trevor.bernard at gmail.com> wrote:
> I've used ngrep and ncat with great success in the past to debug
> zeromq connectivity issues
>
> On Mon, Dec 1, 2014 at 5:42 PM, Andreas Bauer <dabukster at gmail.com> wrote:
>> The code for the test cases is just the one I’ve already attached. Really
>> nothing more.
>>
>> But true, it was a strange network issue. I’ve overlooked that my test
>> server’s firewall (Macbook) hat an accepting but also a denying rule for
>> incoming traffic for java programs… Sometime, just talking about a problem,
>> helps :)
>>
>>
>> Am 1. Dezember 2014 bei 15:11:11, Hintjens Pieter (ph at imatix.com) schrieb:
>>
>> Could you provide complete minimal test cases for both sides?
>>
>> As you move pieces to remote boxes, some things take more time. Could
>> just be that, nothing weird at the network level.
>>
>> -Pieter
>>
>> On Sat, Nov 29, 2014 at 5:22 PM, Andreas Bauer <dabukster at gmail.com> wrote:
>>> Hi,
>>>
>>> it’s one of the standard and basic „can’t receive message" problem
>>> questions, but I’m not able to spot the error...
>>>
>>> I have implemented a simple client and a server using PUB/SUB in java
>>> using
>>> jeromq 0.3.2 according to the examples in the wiki.
>>>
>>> If I execute both programms locally, the client receives data. If I deploy
>>> the same client jar without change on a remote computer and run it, I
>>> don't
>>> receive any messages.
>>>
>>> The client is always using the ip (not „localhost" as hard coded string)
>>> of
>>> the server in both cases. Thus no changes here for the remote deployment.
>>>
>>> Firewall should not be an issue either, as the netstat excerpt below shows
>>> (Interestingly netstat -a for 0.3.2 shows the below entry, 0.3.4 does
>>> not…).
>>> The server (for test purpose my Macbook Air) does also not block any
>>> outgoing traffic.
>>>
>>> Any hints? Somehow I'm not able to spot the error (probably something
>>> stupid, but too blind to see…)
>>>
>>> Server.java
>>>
>>> ZMQ.Context context = ZMQ.context(1);
>>> ZMQ.Socket publisher = context.socket(ZMQ.PUB);
>>> publisher.bind("tcp://*:5556");
>>>
>>>
>>> Client.java
>>>
>>> ZMQ.Context context = ZMQ.context(1);
>>> ZMQ.Socket subscriber = zmqContext.socket(ZMQ.SUB);
>>> subscriber.connect("tcp://192.168.178.21:5556");
>>> subscriber.subscribe("".getBytes());
>>> Firewall shouldn't be an issue either
>>>
>>> netstat -a | grep 5556
>>>
>>> says
>>>
>>> tcp 0 1 192.168.178.29:38145 192.168.178.21:5556 SYN_SENT
>>>
>>>
>>> Finally my iptables config, just in case I made a stupid configuration
>>> mistake here.
>>>
>>> *filter
>>> :INPUT DROP [0:0]
>>> :FORWARD ACCEPT [0:0]
>>> :OUTPUT ACCEPT [1161:105847]
>>> -A INPUT -i lo -j ACCEPT
>>> -A INPUT -s 192.168.178.0/24 -j ACCEPT
>>> COMMIT
>>>
>>> Best regards,
>>>
>>> Andreas
>>>
>>> _______________________________________________
>>> zeromq-dev mailing list
>>> zeromq-dev at lists.zeromq.org
>>> http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>>>
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